Boise (BOI) to Seattle (SEA): On-Time Performance
Data through July 2026
The calendar drives reliability on BOI–SEA. February 2026 flights landed on schedule 93% of the time, but February 2025 dropped to 73% — a gap of 20 points. Across the full period the route averages 84% on-time against a national 78%. Morning departures also hold up better than evening ones (88% vs 76%), which matters most in the rough months.
- On-time
- 84%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 0.3%
- Flights/day
- 10
- last 12 months
- Duration
- 1h 45m
- scheduled
- Distance
- 399 mi
Best airline from BOI to SEA
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| SkyWest Airlinesmost reliable | 84% | 9 min | 0.2% | 6,150 |
| Alaska Airlines | 81% | 10 min | 0.7% | 1,627 |
Monthly on-time trend
Best time to fly from BOI to SEA
Aim for departures around 5 a.m. (93% on-time); avoid 8 p.m. departures (52%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 85% | 9 min |
| Tuesdaybest | 88% | 7 min |
| Wednesday | 84% | 9 min |
| Thursday | 80% | 12 min |
| Friday | 81% | 12 min |
| Saturday | 87% | 8 min |
| Sunday | 82% | 11 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft17%
- Airline operations49%
- National airspace system23%
- Weather11%
Frequently asked questions
- How often are flights from BOI to SEA delayed?
- 16% of BOI–SEA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 10 minutes.
- Which airline is most reliable from BOI to SEA?
- SkyWest Airlines has the best on-time record on this route at 84%, based on 6,150 flights. 2 airlines flew BOI–SEA frequently enough to compare in this period.
- What is the best time of day to fly from BOI to SEA?
- Departures around 5 a.m. have the best record (93% on-time), while departures around 8 p.m. have the worst (52%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from BOI to SEA?
- The scheduled BOI–SEA flight time averages 1h 45m over 399 miles. Actual arrival times vary — flights on this route land 15+ minutes late 16% of the time.
- How often are BOI to SEA flights cancelled?
- 0.3% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from BOI to SEA?
- February 2025 was the roughest month in this dataset, with only 73% of arrivals on time. The best was February 2026 at 93%. If your dates are flexible, that 20-point gap is worth planning around.
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Based on 7,778 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.